There are a number of photo management applications that provide solutions for organizing, previewing, editing and managing collections of images of people. Some of these applications employ face detection and recognition techniques to assist users with the organization and management of the images. For instance, face recognition systems can be used to locate the face of a person within an image that may include other objects or people. In some cases, such systems can further analyze the face in one image and match it to the face of the same person in other images. For example, selected facial features of a person may be extracted from a given image and compared to the facial features extracted from other images in a database of known faces. A number of non-trivial issues are associated with managing and organizing digital images, particularly when face recognition is used.
When using a photo management application to organize and manage images of people, there may be instances where it is desirable to group the photos together so that a given subject appears in every photo of the group. Such groupings allow a user to more easily locate all photos containing the given subject. Separate groups of photos may be created for every subject appearing in the set of photos. Once the photos are grouped, one photo in each group may be selected to represent all of the photos in the group. For example, the representative photo may be a portrait or head shot of the subject appearing in the all of the photos in the group. The representative photo may be displayed in a GUI of the photo management application so that the user can easily locate all of the photos of that subject. However, the quality of photographs typically varies such that some photos are more visually or aesthetically appealing than others. For example, some photos may be dark, blurry, off-center, or otherwise include aesthetically displeasing qualities, such as poor facial expressions, uneven exposure, or harsh colors. Such low quality photos may not be suitable for use as a representative photo for visual or aesthetic reasons, especially when the group includes better quality photos that could instead be used as representative photos.
When a user manually selects the representative photo for a group of photos, the user will typically choose the best photo of the group, such as the photo that has the best combination of exposure, color, facial expression, focus and resolution. It is also possible to automatically select the representative photo so that the user does not have to select it manually. However, automatically selecting the best or most representative photo is not a simple task. For example, a suboptimal algorithm may merely choose the photo that is the oldest in the group, newest in the group, or most recently added in the group, without considering any of the visual or aesthetic qualities of the photo. As a result, such algorithms may select, as the representative image, a photo that does not necessarily have the best combination of attributes among all of the photos in the group.